On the Need for Post-Processing

Jun 20th, 2012

For most of my life I’ve been a film photographer. In those days the mantra I followed was that when I pressed the shutter, my job was essentially done. I’d send my K64 film off to Kodak, get my transparencies back a week later, present them to my editors and cash my check. Done.

Not anymore. In today’s digital age, I figure my job is maybe 25-50% done when I press that shutter button. Even though I really do not do much post-processing, digitally captured images do need some tweaking, especially if you are shooting in RAW with settings on ‘neutral.’ The truth is I don’t even know how to use PhotoShop. I entered the digital game too late in life to teach this old dog tricks of that complexity, although I admit to a certain degree of envy when I watch my assistant, Bob, handle PhotoShop like it was an extension of his fingers. Instead, I post-process in Lightroom and, if needed, use the Nik software line of products to do some tweaking. Mostly that involves just using Viveza.

However, there are some instances where you just have to do some significant post-processing and this past week was one of them. I thought I’d share that with you.

When I was in Iceland, I was shooting some waterfalls with both my Hasselblad H4D-50 and my new Nikon D800. On each lens I had a polarizer, so I could fine tune the reflections in the water. A polarizer reduces the amount of light hitting the sensor by about 1 stop or maybe a bit more, which was good in this case because I wanted the water to have a smooth look to it which you can only achieve with a very slow shutter speed.

In fact, I did not like the results I was getting. I wanted to slow the water down even more. But I was already shooting at ISO 50 on the Hassy, the lowest setting it would take. So, I added a 4-stop neutral density filter, meaning I was holding back about 4 stops of light. ND filters block light hitting the sensor without causing color shifts. Or that is what they are supposed to do.

I got my slowed down water movement all right. But when I got home and examined my images, I saw that they had a very pronounced color cast. They all had a yucky (that’s a technical term, btw) pink-magenta cast.

We picked up the phone to talk to the incredible Bob Singh, the maker of Singh-Ray filters. Bob is one of the most knowledgeable people in the industry and while his products are costly, they are high quality all the way and backed by Bob’s technical genius.

Without getting too technical, it turns out that the ND filter I was using blocked out visible light in a different proportion to the infrared (IR) light, and that was responsible for the color shift. The solution was simple. Bob could make a filter that filtered both sets of wavelengths so that this would not happen again. I ordered one immediately. I’m a believer in getting it right in-camera and not digitally manipulating the image after the fact.

But, what to do with the images I already had? In this case Bob (my assistant) worked his magic in PhotoShop CS6. It took quite a bit of doing, messing with color channels and temperatures and such, but in the end he was able to render the scene pretty near what I had experienced, which is the image that follows. That pretty well reinforces my belief that in some situations post-processing work is an effective and necessary tool.